The photoacoustic effect relates to the formation of sound waves, following light absorption in a medium. In order to obtain this effect, the light intensity is varied. The photoacoustic effect can be quantified by measuring the formed sound (e.g. pressure changes) with appropriate detectors. The time variation of the electric output from these detectors can be called photoacoustic signal. These measurements can be used to determine certain properties of the studied medium. For example, the composition of gas can be analyzed. It is desired to implement a photoacoustic gas sensor concept providing high accuracy with low effort.